I go for the third reason ;) Yes, it is good that you can start earning a little extra to help your parents but always bear in mind after the opening of classes, you should know how to prioritize:

Your entry as a college student will e very crucial. Here you will learn a lot of your basics which will be useful in the future. Do not take this first year for granted, believe me, you will find them handy. Fundamentals will truly help you along your career.

Games to unwind versus PC. If you are torn between funding for both, choose the one which will be more beneficial for you in the long run.

Learning or Earning. You will eventually start to earn after school, so take this from suggestion from me: give more priority over your studies than any other sidelines. You can help you parents financially in a number of ways but please do not compromise your education. The competition in this world is becoming more and more intense and technology based thus you need a good educational background to develop more. Your spare time can be enough for some side jobs :)

Good luck and hope these suggestions help. :)